Cheats List
Beat the game once, and these codes will unlock. To make them work, go to the pause menu, hold all of the shoulder buttons (R1, R2, L1, L2), then press the buttons listed below to activate the corresponding cheat:
Invulnerability - SQUARE, CIRCLE, SQUARE, UP
Restore Health - SQUARE, SQUARE, CIRCLE, CIRCLE
All Upgrades - UP, DOWN, TRIANGLE, SQUARE
Infinite Missiles - SQUARE, SQUARE, DOWN, CIRCLE
Always Devastating - TRIANGLE, UP, TRIANGLE, DOWN
Perfect Mode - CIRCLE, DOWN, TRIANGLE, X
Targeting Indicator Mode - DOWN, CIRCLE, UP, SQUARE
JonR2006 maintains he has the solution for LotR:RotK end of the game codes. He states that once you have beaten Return of the King, the codes at the end of the game don't work. Everytime there is a DOWN, UP, RIGHT, or LEFT entry to press when putting in the code, you have to do the exact opposite.